The family of paedophile Craig Sweeney's three-year-old victim have said they are to take legal action against South Wales Police. The girl's mother claimed police had failed to protect her from a "known and dangerous child molester".
She wants "the book thrown" at those responsible after the Independent Police Complaints Authority partially upheld the family's complaint.
The force's chief constable said "clearly" the family had been let down.
The IPCC found part of the girl's ordeal could have been prevented.
Its report said a faster response of "prompt and appropriate action" may have spared her from the second phase of Sweeney's "monstrous" actions.
I have apologised to the child and her family, as clearly, we let them down
The mother said police could have got to Sweeney before the assault began.
In the moments after the girl was snatched from her home in Rumney, Cardiff, the mother called the police, told them Sweeney's name and that he was from the area originally but now lived in Newport.
The child was repeatedly assaulted by Sweeney at his hostel in Newport before he drove off with her to Wiltshire.
He was only caught after a high-speed chase sparked when police saw him driving through a red traffic signal without his headlights turned on.
The girl's mother said: "The only thing the police couldn't have stopped is her being taken from her house but the rest could have been prevented," she said.
"They could have been where Sweeney was staying before he even got there."
However the IPCC in its report found insubstantial evidence to support this claim, but did find faster action may have prevented Sweeney from leaving the flat in Newport with the child.
She was relieved the inquiry found "it wasn't all my fault", but said: "I'm also angry that they (South Wales Police) didn't protect my daughter.
"I hope whoever is responsible now has the book thrown at them. They would've loved this one to be brushed under the carpet."
She described South Wales Police as "diabolical" adding: "If you can't trust the police then who can you trust?"
She continued: "I think it's worse than a death because with a death you can grieve but I have to stay strong and I can't cry in front of the kids."
"If I fell apart then the whole family would fall apart. I haven't shed a tear because if I did I wouldn't stop.
"My kids are no longer allowed in the front garden anymore because I'm much more wary.
"It's as if they are prisoners in their own home because I'm very jumpy if a car pulls up outside.
"I have to go around the house to make sure all the doors and windows are shut.
The family is considering a move abroad to Spain "to escape the nightmare".
She added: "At some point a person will break and I think I have to do something before I get to breaking point."
South Wales chief constable Barbara Wilding said on Wednesday she had apologised to the family in person and tried to reassure parents in the area.
She told a news conference that "the initial confusion" that surrounded the incident "was not dealt with as effectively as it should have been".
"In that regard, I have apologised to the child and her family, as clearly, we let them down - and for this I am very sorry," she said.